* Daring raid follows government offensive
* Colonel among dead
* Concerned U.S. backs Yememi goverment, military (Updates with details on raid)
By Mohammed Ghobari
SANAA, May 14 (Reuters) - At least eight Yemeni soldiers and 10 al Qaeda militants were killed in clashes on Wednesday when insurgents attacked two military posts in a southern province where the government mounted an offensive two weeks ago, military sources said.
The sources told Reuters the fighting in Gol al-Rayda and Azzan districts of Shabwa province started early in the morning and raged for several hours. An army colonel was among the dead, a Defence Ministry source said.
The Yemeni army had captured both Gol al-Rayda and Azzan, as well as the Mahfad district in Abyan province, earlier this month after heavy fighting in which scores were killed on both sides.
Many of the militants, from Al Qaeda in the Arabian Peninsula (AQAP) and its affiliate, Ansar al-Sharia, fled to the mountains and turned to hit-and-run tactics against security forces and government facilities across the country. Wednesday's raid was one of the most daring actions since then.
A military source in Azzam said that eight soldiers and 10 al Qaeda militants were killed in the fighting. Air force planes were also striking at fleeing militants, he added.
A Yemeni journalist who specialises in covering al Qaeda, Abdulrazzaq al-Jamal, reported on his Facebook page that the militants killed soldiers at a checkpoint and raised a black flag inscribed with the words "There is no god but God and Mohammed is his Prophet" on the main police station in Azzan.
Residents also said that many people were forced to stay indoors as sounds of clashes rang out over the town.
Military sources in the field said the army forced the militants to retreat, and they took with them the bodies of their dead or wounded.
Five militant vehicles were destroyed, the Defence Ministry said. Government forces also captured a number of the militants in Azzan, who were found in possession of "documents, bombs and explosives belts", it said.
Stability of Yemen, which shares a long border with the world's top oil exporter, Saudi Arabia, is an international concern. The United States has stepped up its aid and support for the government and military, including drone strikes.
The country is trying to recover from political turmoil which began in 2011 when mass protests, part of the Arab Spring that began in North Africa, forced long-ruling president Ali Abdullah Saleh to step down.
Last week, a gunbattle with militants took place near the presidential palace in Sanaa. Four soldiers were killed.
On Sunday a suicide bomber rammed a car packed with explosives into a military police building in the coastal city of Mukalla, killing at least 10 soldiers and a civilian.
Apart from the militant threat, impoverished Yemen is trying to cope with separatist demands in the south and a rebel group in the north. (Additional reporting by Mohammed Mukhashaf in Aden, writing by Sami Aboudi; Editing by Angus MacSwan)